1. Field of the Invention
The present invention relates to a mobile radio communication apparatus including a portable telephone apparatus or a code-less telephone apparatus, more particularly to a cellular mobile telephone apparatus and an alarm device therefor, by which so called a call termination is alerted separately from a main body thereof.
2. Description of Related Art
Recently, there is available a cellular mobile telephone apparatus which alarms the call termination to a user thereof, not by a sound but through vibration thereof, so as not to disturb people around him/her by issuing the alarming sound. With such cellular mobile telephone apparatus, it must be closely touched with a body of the user so that he/she can sense the vibration. However, according to the present technical level, it is difficult to miniaturize and lighten the telephone apparatus so that it can be used comfortably even in condition that it is closely touched with the body.
For that reason, a small-sized device for alarming the call termination has been conceived, which is separately provided from the main body of the cellular mobile telephone apparatus. With this small-sized device, even if the main body of the cellular mobile telephone apparatus is put into a bag or the like, the user of the cellular mobile telephone apparatus can notice the call to his/her own telephone apparatus without disturbing the people around by the alarm sound, since it notifies the call termination thereto through it's vibration, as far as it is used closely touched with the body of the user.
Such alarming device, operates if it detects a transmitted signal, which signal is transmitted from the main body of the mobile telephone apparatus when it receives a call signal from the base station and sends back a termination signal for it, in a field of a mobile telephone system or a so-called personal phone system. Also, in Japanese Patent Laying-Open No. 6-21875 (1994), there is disclosed a cellular mobile telephone apparatus having an auxiliary device or unit for alarming the call termination through vibration, which is provided separately from the main body and connected through a cable or a radio frequency signal therebetween.
However, in the prior art mentioned above, since there is not necessarily established a relationship between the cellular mobile telephone apparatus and the alarm device or auxiliary unit in a one-to-one correspondence, there is a drawback that the alarm device confuses and erroneously starts vibration responding to the transmitted signal of noticing the call termination from the mobile telephone apparatus of others, in particular when it is located or used in the vicinity thereof.
Further, information which can be obtained from the alarm device by the vibration is limited to call termination of his/her own cellular mobile telephone apparatus. Therefore, there are other drawbacks that the main body of the cellular mobile telephone apparatus generates an alarm sound when the battery thereof comes near to be exhausted for notifying it to the user, thereby disturbing the other people around, and that when the user who is carrying the alarm device with him/her is away from his/her own cellular mobile telephone apparatus, he/she fails to hear the arisen alarm sound, nor to notice that it is in the condition that it cannot respond to a call any more because of the exhaustion of the battery.